Silver halide emulsion sensitized with noble metal and sugar mercapto compound

ABSTRACT

The present invention is directed to an improved sensitizer for silver halide light-sensitive emulsions which comprises a mixture of a noble metal sensitizer and a sugar derivative such as sugar alkyl mercaptals, sugar aryl mercaptals, alkyl thioglycosides and aryl thioglycosides. Particularly preferred are the combination of gold sensitizers and sugar derivatives. Specific examples of such derivatives are glucose dimethylmercaptal, xylose diethylmercaptal and lactose dimethylmercaptal.

United States Patent Ohiet al.

[541 SILVER HALIDE EMULSION SENSITIZED WITH NOBLE METAL AND SUGAR MERCAPTO COMPOUND [72] Inventors: Reiichi Ohl; Toitiharu Kondo; Mitsunorl Suglyama; Shiguro Syojl, all of Kanagawa,

Japan [73] Assignee: Fuji Photo Film Co., Ltd., Kanagawa,

Japan [22] Filed: July8, 1969 [2]] App], No.: 840,021

2,597,856 S/l952 Damschroder ..96/l08 [451 Jan. 18, 1972 FOREIGN PATENTS OR APPLICATIONS l,l84,l38 3Il970 Great Britain ..96/i08 Primary Examiner-Norman G. Torchin Assistant Examiner-Won H. Louie, Jr. Attomey-Sughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT The present invention is directed to an improved sensitizer for silver halide light-sensitive emulsions which comprises a mixture of a noble metal sensitizer and a sugar derivative such as sugar alkyl mercaptals, sugar aryl mercaptals, alkyl thioglycosides and aryl thioglycosides. Particularly preferred are the combination of gold sensitizers and sugar derivatives. Specific examples of such derivatives are glucose dimethylmercaptal, xylose diethylmercaptal and lactose dimethylmercaptal.

15 Claims, No Drawings SILVER HALIDE EMULSlON SENSITIZED WITH NOBLE METAL AND SUGAR MERCAPTO COMPOUND BACKGROUND OF THE INVENTION 1. Field of the Invention 5 This invention relates to a silver halide photographic lightsensitive emulsion and more particularly to a silver halide photographic light-sensitive emulsion sensitized with a noble metal sensitizer such as gold salt.

2. Description of the Prior Art Various methods for raising the sensitivity of a silver halide photographic light-sensitive emulsion have been studied and a number of compounds have been proposed as sensitizing materials to be added during preparation of silver halide lightsensitive emulsions. The most commonly used of these materials are active sulfur-containing compounds called sulfur sensitizers," water-soluble noble metal compounds called noble metal sensitizers" and polyalkylene oxide derivatives. In many cases, these compounds may be used in combination.

The present invention relates to an improvement in silver halide sensitization in which water-soluble metal compounds such as gold salt are used. Water-soluble noble metal compounds have been proposed as sensitieers. The most widely used of these compounds, however, are chloroauric acid and salts thereof, which are often used together with potassium rhodanate where further sensitivity is required. The results of our experiments, however, show that such joint use with potassium rhodanate tends to deteriorate the storage property of a photographic light-sensitive material after production and to accelerate fog formation during storage.

lt is an object of the invention to provide an improved silver halide photographic lighbsensitive emulsion which is mar- SUMMARY OF THE INVENTION The above-mentioned objects can be accomplished by incorporating a sugar mercaptal derivative or a thioglycoside derivative into a silver halide photographic emulsion containing a noble metal sensitizer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As the noble metal sensitizer for the invention there can be used well-known gold sensitizers as well as platinum sensitizers and the like.

Illustrative of the gold sensitizers are gold chloride, potassium aerate, potassium auricyanide, potassium aurithiocyanate, gold sulfide, pld selenide, gold iodide, potassium chloroaurate and ethylenediamine-bis-gold chloride.

The sugar mercaptal derivatives and thioglycoside derivatives used in the invention are not particularly limited, but the use of allrylor aryl-mercaptals of monosaecharides or disaccharides, or allrylor aryl-thioglycosides is preferred. The foregoing derivatives can be synthesized by the method described in Berichte, 27, 673 (I894), .I.A.C.S., 53. 4,379 (1931 and Berichte, 49, 2,056( l9l6).

Typical examples of these compounds are as follows:

Compound M.P., C.

1 Glucose diethylmercaptal -131 (!)H SCgHll Cl1HzOH-CHCHCHCH OH OH OH OH SaCHr 2 Xyloso diethylmercapta] 60-62 OH SCI I CHzCH-CH(IIHCH OH OH OH SCzHs 3 Lactose diethylmercaptal 128-12!) SCIHB CH\ OH SO11], GHiOH CH-OH CH-0 \r** H OH OH CH H() H i\| 11,011 OH (EH-OH 0H 4 Glucose dlphenylmercaptal 160461 I 1CH2CH-CHCH-(|1H-CH\ OH on OH OH s@ 5 Glucose dibenzylmercaptal -141 l l I Compound M.P., C. s Q. Ethyl thioglyeoslda 157-168 I /CHOCH'- S CrHs CH 011 l i H H-(fll OH One or more of these compounds are added during the The results areasfollows. preparation of the silver halide photographic light-sensitive material. preferably, before or during chemical ripening in a Sample A Sample a Sample 0 proportion of 0001-01 mole per mole, preferably 3 143 o as 0.002-0.0i mole per mole. of silver halide. The sugar mercap- 6mm H6 H3 H9 tal derivative or thioglycoside compound and a noble metal sensitizer such as chloroauric acid may be added in order and, EXAMPLE 2 preferably, a solution of the derivative and a solution of chloroauric acid are previously admixed and the mixed solution added to an emulsion.

As the silver halide of the invention. silver chloride, silver bromide, silver iodide or mixed silver halide such as silver iodobromide is used.

into the silver halide photographic light-sensitive emulsion. of the invention there may further be incorporated chemical sensitizers such as active sulfur compounds or polyalkylene oxide derivatives, spectral sensitizing dyes such as cyanines, merocyanines or rhodacyanines, and fog inhibitors such as organic mercapto compounds or tetrazainedene compounds.

The silver halide photographic light-sensitive emulsion of the invention is applicable not only to white-and-black photographic light-sensitive materials but also to color photographic light-sensitive materials.

The following examples are given in order to illustrate the invention in detail without limiting the same.

in the same emulsion as in example i, chloroauric acid and compound 6 were used and comparison was carried out with an emulsion wherein potassium rhodanate was used in place of compound 6.

Sample A: 12 ml. of 0.01 percent aqueous solution of chloroauric acid and 6 ml. of 1 percent aqueous solution of potassium rhodanate were mixed, added per kg. of the emulsion and subjected to chemical ripening at 50 C. for 60 minutes.

Sample B: Prepared in the same manner as sample A except that ml. of 0.01 mol methanol solution of compound 6 was used in place of potassium rhodanate.

Sample C: Prepared in the same manner as sample A except that 30 ml. of 0.04 mol methanol solution of compound 6 was used in place of potassium rhodanate.

The resulting samples were processed in the same manner as in example i to give the following results.

Relative sensitivity Fog Gamma Sample A B C A B C A B C immediately after coating and titling 100 105 118 0.06 0.06 0.06 0.00 0.60 0.63

. l0% HAL, alter standing Iorflduys 100 113 155 0.55 0.20 0.25 0.00 0.55 0.50

50 0., 10% RH, aftor standing i0 7duys 133 135 0.55 0.20 0.24 0.00 0.53 0.00

EXAMPLE I A high sensitivity geiatino-silver iodobromide emulsion containing a sulfur sensitizer prepared in the conventional manner (silver: 22 g. per 1 kg. of emulsion, iodide: 5 mole percent) was processed by the following procedures to obtain Samples A, B and C.

Sample A: Chemical ripening at 50 C. for minutes Sample B: 36 ml. of 0.01 percent aqueous solution of chloroauric acid was mixed with 10 ml. of 0.1 mole methanol solution of compound i, added per kg. of the emulsion and subjected to chemical ripening at 50 C. for 60 minutes.

Sample C: Prepared in the same manner as in sample 8 except that 90 ml. of the solution of compound 1 was used.

Each of the samples thus obtained was coated onto a glass plate, dried, developed at 20 C. for 8 minutes with a developer having the composition as set out below, fixed. washed with water and then dried.

Developer N mstliylperunlnephsnol sulfate 2 g. anhydrous sodium sullltu I00 3. hydroquinone 5 g. born 2 water to make l l.

EXAMPLE 3 in the same emulsion as in example i, chloroauric acid and compound 3 were used and a comparison was carried out with an emulsion wherein chloroauric acid alone was added.

Sample A: l2 ml. of 0.0l percent aqueous solution of chloroauric acid was added per kg. of emulsion and and subjected to chemical ripening at 50 C. for 60 minutes. Sample B: 12 ml. of 0.0l percent aqueous solution of chloroauric acid and 13 ml. of 0.02 mol methanol solution of compound 3 were added per kg. of the emulsion and subjected to chemical ripening at 50 C. for 60 minutes. Sample C: Prepared in the same manner as sample B except that 20 ml. of the solution of compound 3 was used. Sample D: Prepared in the same manner as sample B except that 30 ml. of the solution of compound 3 was used. The resulting samples were processed in the same manner as in example i to give the following results.

An ammonia process high sensitivity gelatino-silver iodide ammoniacal emulsion containing a sulfur sensitizer was prepared in the conventional manner (silver: 40 g. per 1 kg. of the emulsion, iodide: l.5 mole percent), divided into four parts, and processed by the following procedures to obtain samples A, B, C, and D.

Sample A: Chemical ripening at 51C. for 60 minutes.

Sample B: 3 ml. of 0.01 percent aqueous solution of chloroauric acid and 100 ml. of 0.01 mole methanol solution of compound I were mixed and added per kg. of the emulsion and subjected to chemical ripening at 51 C. for 60 minutes.

Sample C: Prepared in the same manner as sample B except that 80 ml. of 0.1 methanol solution of compound I was used.

Sample D: Prepared in the same manner as sample B except that 50 ml. of 0.01 mol methanol solution of compound 4 was added.

Each of the thus obtained samples was coated onto a glass plate, dried, developed with a developing solution having the following composition at 20 C. for 6 minutes, fixed washed with water and then dried.

A gclatino-silver chlorobromide fine grain positive emulsion containing a sulfur sensitizer and prepared in the conventional manner (silver: l9 g. per kg. of the emulsion, bromide: 50 mole percent) was divided into two portions and processed by the following procedures to obtain sample A and sample B. Sample A: Chemical ripening at 52 C. for 60 minutes. Sample 8: 18 ml. of 0.01 percent aqueous solution of chloroauric acid and 50 ml. of 0.02 mol percent methanol solution of compound 4 were mixed, added per kg. of the emulsion and subjected to chemical ripening at 52 C. for 60 minutes.

Each of the thus obtained samples were coated onto a glass plate, dried, developed at 20 C. for 4 minutes with a developing solution having the following composition, fixed, washed with water and dried.

Developer water to make I l.

The results are as follows:

Sample A Sample B Relative sensitivity I00 I26 Fe. 0.05 0.04

Gamma ,7, WW, 7 W, 2.55 2.48

What is claimed is:

l. A silver halide photographic light-sensitive emulsion having incorporated therein a noble metal sensitizcr and at least one sugar derivative selected from the class consisting of sugar alkyl mercaptals, sugar aryl mercaptals, alkyl thioglycosides and aryl thioglycosides.

2. Silver halide photographic light-sensitive emulsion of claim 1 wherein said sugar derivative is glucose diethylmercaptal.

3. Silver halide photographic light-sensitive emulsion of claim I wherein said sugar derivative is xylose diethylmercapta].

4. Silver halide photographic light-sensitive emulsion of claim I wherein said sugar derivative is lactose diethylmercapta].

5. Silver halide photographic light-sensitive emulsion of claim 1 wherein said sugar derivative is glucose diphenylmercaptal.

6. Silver halide photographic light-sensitive emulsion of claim I wherein said sugar derivative is glucose dibenzylmercaptal.

7. Silver halide photographic light-sensitive emulsion of claim 1 wherein said sugar derivative is ethyl thioglycoside.

8. Silver halide photographic light-sensitive emulsion of claim I wherein said noble metal sensitizer is selected from the class consisting of gold chloride, potassium aurate, potassium auricyanide, potassium aurithiocyanate, gold sulfide, gold selenide, gold iodide, potassium chloroaurate and ethylenediamine-bis-gold chloride.

9. Silver halide photographic light-sensitive emulsion of claim I wherein said at least one sugar derivative is present in an amount of 0.00l-0.l mole of said sugar derivative per mole of silver halide.

10. Silver halide photographic light-sensitive emulsion of claim 1 wherein said noble metal sensitizer is a gold sensitizer.

ll. Silver halide photographic light-sensitive emulsion of claim 1 wherein said noble metal sensitizer is a water-soluble noble metal sensitiaer.

12. Silver halide photographic light-sensitive emulsion of claim I wherein said silver halide is selected from the group consisting of silver chloride, silver bromide, silver iodine and mixed silver halides.

13. Silver halide photographic light-sensitive emulsion of claim 12 wherein said mixed silver halide is silver iodobromide.

14. Silver halide photographic light-sensitive emulsion of claim I wherein said noble metal sensitizer is chloroauric acid.

15. Silver halide photographic light-sensitive emulsion of claim 1 wherein said sugar is selected from the group consisting of a monsaccharide and a disaccharide.

F t i 1 i 

2. Silver halide photographic light-sensitive emulsion of claim 1 wherein said sugar derivative is glucose diethylmercaptal.
 3. Silver halide photographic light-sensitive emulsion of claim 1 wherein said sugar derivative is xylose diethylmercaptal.
 4. Silver halide photographic light-sensitive emulsion of claim 1 wherein said sugar derivative is lactose diethylmercaptal.
 5. Silver halide photographic light-sensitive emulsion of claim 1 wherein said sugar derivative is glucose diphenylmercaptal.
 6. Silver halide photographic light-sensitive emulsion of claim 1 wherein said sugar derivative is glucose dibenzylmercaptal.
 7. Silver halide photographic light-sensitive emulsion of claim 1 wherein said sugar derivative is ethyl thioglycoside.
 8. Silver halide photographic light-sensitive emulsion of claim 1 wherein said noble metal sensitizer is selected from the class consisting of gold chloride, potassium aurate, potassium auricyanide, potassium aurithiocyanate, gold sulfide, gold selenide, gold iodide, potassium chloroaurate and ethylenediamine-bis-gold chloride.
 9. Silver halide photographic light-sensitive emulsion of claim 1 wherein said at least one sugar derivative is present in an amount of 0.001-0.1 mole of said sugar derivative per mole of silver halide.
 10. Silver halide photographic light-sensitive emulsion of claim 1 wherein said noble metal sensitizer is a gold sensitizer.
 11. Silver halide photographic light-sensitive emulsion of claim 1 wherein said noble metal sensitizer is a water-soluble noble metal sensitizer.
 12. Silver halide photographic light-sensitive emulsion of claim 1 wherein said silver halide is selected from the group consisting of silver chloride, silver bromide, silver iodine and mixed silver halides.
 13. Silver halide photographic light-sensitive emulsion of claim 12 wherein said mixed silver halide is silver iodobromide.
 14. Silver halide photographic light-sensitive emulsion of claim 1 wherein said noble metal sensitizer is chloroauric acid.
 15. Silver halide photographic light-sensitive emulsion of claim 1 wherein said sugar is selected from the group consisting of a monsaccharide and a disaccharide. 